The present invention relates to the use of specific retinoids in the preparation of a pharmaceutical composition which is intended to increase the rate of apoptosis. These retinoids can also be used in cosmetic compositions which are intended, in particular, to prevent and/or combat photoinduced or chronological ageing of the skin.
Two types of mechanism are involved in the death of cells. The first, which is the classical type, is termed necrosis. Morphologically, necrosis is characterized by swelling of the mitochondria and the cytoplasm and by nuclear distortion, followed by destruction of the cell and its autolysis, with the latter being accompanied by an inflammation phenomenon. Necrosis occurs in a passive and incidental manner. Tissue necrosis is generally due to the cells being subjected to a physical trauma, or due to a chemical poison, for example.
The other form of cell death is termed apoptosis [Kerr, J. F. R. and Wyllie, A. H., Br. J. Cancer, 265, 239 (1972)]; however, contrary to necrosis, apoptosis does not result in any inflammation phenomenon. Apoptosis has been reported to be able to take place under various physiological conditions. It is a highly selective form of cell suicide which is characterized by readily observable morphological and biochemical phenomena. Thus, condensation of the chromatin, which is or is not associated with an endonuclease activity, formation of apoptotic bodies and fragmentation of the deoxyribonucleic acid (DNA), by activation of endonucleases, into 180-200 base pair DNA fragments (these fragments can be observed by means of agarose gel electrophoresis) are, in particular, observed.
Apoptosis can be regarded as being a programmed cell death which is involved in tissue development, differentiation and renewal. It is also thought that the differentiation, growth and maturation of cells are closely linked to apoptosis and that the substances which are able to play a role in the differentiation, growth and maturation of cells are also linked to the phenomenon of apoptosis.
In the medical field, some pathological situations exhibit a modified, if not deregulated, apoptosis mechanism. Thus, it has been reported that deliberate modulation of apoptosis, by inducing it or suppressing it, can make it possible to treat a large number of diseases, more specifically diseases linked to cell hyperproliferation, as in the case of cancer, autoimmune diseases and allergies, or, on the other hand, diseases which are linked to cell disappearance, as in the case of the human immunodeficiency virus (HIV) immunodeficiency syndrome, neurodegenerative diseases (Alzheimer""s disease) or excessive damage which is induced during myocardial infarction.
Specifically, it has been noted in oncology that a large number of antineoplastic drugs, such as dexamethasone, cyclophosphamide and cisplatin, are able to induce apoptosis.
In the cosmetic field, the signs of cutaneous ageing essentially result from dysfunction of the principal biological mechanisms of the skin which, in particular, bring the mechanism of apoptosis into play. It is possible, therefore, to imagine that any product which induces the mechanism of apoptosis is a product which is suitable for preventing and/or combating the appearance of ageing and the existing signs of ageing such as large and small wrinkles.
In the field of retinoids, it is known that all-trans retinoic acid is a powerful modulator (i.e. an inhibitor or, on the other hand, a stimulator, depending on the nature of the cells which are treated) of the differentiation and proliferation of many normal or transformed cell types. For example, it inhibits the differentiation of epithelial cells such as the keratinocytes of the epidermis. It also inhibits the proliferation of many transformed cells such as melanoma cells. These effects on proliferation and differentiation can affect one and the same type of cell simultaneously, as is the case, for example, for HL-60 human promyelocytic cells; thus, it is known that proliferation of these cells is inhibited by all-trans retinoic acid and that, at the same time, their differentiation into granulocytes and their apoptosis are induced.
It is known, in a general manner, that all-trans retinoic acid acts on the differentiation and proliferation of cells by interacting with nucleoreceptors which are termed RARs (retinoic acid receptors) and which are present in the cell nucleus. To date, three subtypes of RAR receptors, termed RAR-xcex1, RAR-xcex2 and RAR-xcex3, respectively, have been identified. After having bound the ligand (i.e. all-trans retinoic acid), these receptors interact with specific response elements (RARE) in the promoter region of genes which are regulated by retinoic acid. In order to bind to the response elements, the RARs heterodimerize with another type of receptor known as RXR receptors. The natural ligand of the RXRs is 9-cis-retinoic acid. The RXRs are regarded as being master regulatory proteins because they interact with other members of the steroid/thyroid receptor superfamily, such as the receptor for vitamin D3 (VDR), the receptor for triiodothyroxine (TR) and the PPARs (peroxisome proliferator activated receptors), to form heterodimers, as they do with the RARs. Furthermore, the RXRs are able to interact with specific response elements (RXRE) in the form of homodimers. These complex interactions, and the existence of numerous RAR and RXR receptors which are expressed differently depending on the tissue and the cell type, explain the pleiotropic effects of retinoids in virtually all cells.
Large numbers of synthetic structural analogues of all-trans retinoic acid or of 9-cis-retinoic acid, commonly termed xe2x80x9cretinoidsxe2x80x9d, have so far been described in the literature. Some of these molecules are able to bind to, and specifically activate, the RARs or, on the other hand, the RXRs. Furthermore, some analogues are able to bind to, and activate, a particular subtype (xcex1, xcex2 or xcex3) of RAR receptor. Finally, other analogues do not exhibit any particular selective activity with regard to these different receptors. In this respect, and by way of example, 9-cis-retinoic acid activates both the RARs and the RXRs without any noteworthy selectivity for either of these receptors (nonspecific agonist ligand), whereas all-trans retinoic acid selectively activates the RARs (RAR-specific agonist ligand) without regard to subtype. In a general manner, and qualitatively, a given substance (or ligand) is said to be specific for a given receptor family (or with regard to a particular receptor of this family) when the said substance exhibits an affinity for all the receptors of this family (or, respectively, for the particular receptor of this family) which is stronger than that which it otherwise exhibits for all the receptors of any other family (or, respectively, for all the other receptors, of this same family or not).
It has been reported that 9-cis-retinoic acid and all-trans retinoic acid are modulators of apoptosis (activator or inhibitor of apoptosis depending, in particular, on the cell type) and that 9-cis-retinoic acid is the more active of these two modulators, with it being possible to explain this observation by the fact that 9-cis-retinoic acid activates both the RARs and the RXRS, contrary to all-trans retinoic acid, which only activates the RARs.
In view of that which has been previously stated, it appears to be of interest to find novel modulators of apoptosis.
In this regard, the Applicant has just discovered that agonist ligands which are specific for receptors of the RAR-xcex3 type are excellent inducers of apoptosis in a variety of cell types, more specifically in thymocytes.
Thus, the present invention relates to the use of at least one agonist ligand which is specific for receptors of the RAR-xcex3 type in the preparation of a pharmaceutical composition which is intended to increase the rate of apoptosis in at least one cell population in which apoptosis can be induced by activating receptors of the RAR-xcex3 type.
The invention also relates to the use, in a cosmetic composition, of at least one agonist ligand which is specific for receptors of the RAR-xcex3 type as an inducer of apoptosis in at least one cell population of the skin in which apoptosis can be induced by activating receptors of the RAR-xcex3 type.
Thus, this composition can make it possible to prevent and/or combat photoinduced or chronological ageing of the skin, in particular by eliminating, by means of apoptosis, cells of the skin which exhibit a deficiency in their repair function and which accumulate over time.
The invention therefore relates, finally, to a cosmetic process for preventing and/or combating photoinduced or chronological ageing of the skin, characterized in that an apoptosis-inducing cosmetic composition, such as previously described, is applied to the skin.
The pharmaceutical or cosmetic composition according to the invention comprises a physiologically acceptable medium.
Agonist ligand which is specific for receptors of the RAR-xcex3 type is understood, according to the invention, as meaning any agonist ligand which exhibits a ratio R of the dissociation constant of this ligand for receptors of the RAR-xcex1 type over the dissociation constant of this ligand for receptors of the RAR-xcex3 type which is greater than or equal to 10, and which induces differentiation of F9 cells.
Thus, it is known that all-trans retinoic acid and some of its analogues are able to induce the differentiation of mouse embryonic teratocarcinoma cells (F9 cells); they are therefore regarded as being agonists for the RAR receptors. The secretion of the plasminogen activator which accompanies this differentiation is an index of the biological response of the F9 cells to the retinoids (Skin pharmacol. 1990; 3: pp. 256-267).
The dissociation constants are determined by means of tests which are standard for the skilled person. These tests are described, in particular, in the following references: (1) xe2x80x9cSelective Synthetic Ligands for Nuclear Retinoic Acid Receptor Subtypesxe2x80x9d in RETINOIDS, Progress in Research and Clinical Applications, Chapter 19 (pp 261-267), Marcel Dekker Inc., edited by Maria A. Livrea and Lester Packer; (2) xe2x80x9cSynthetic Retinoids: Receptor Selectivity and Biological Activityxe2x80x9d in Pharmacol Skin, Basel, Karger, 1993, Volume 5, pp 117-127; (3) xe2x80x9cSelective Synthetic Ligands for Human Nuclear Retinoic Acid Receptorsxe2x80x9d in Skin Pharmacology, 1992, Vol. 5, pp 57-65; (4) xe2x80x9cIdentification of Synthetic Retinoids with Selectivity for Human Nuclear Retinoic Acid Receptor-xcex3xe2x80x9d in Biochemical and Biophysical Research Communications, Vol. 186, No. 2, July 1992, pp 977-983; (5) xe2x80x9cSelective High Affinity RAR-xcex1 or RAR-xcex2 Retinoic Acid Receptor Ligandsxe2x80x9d in Mol. Pharmacol., Vol. 40, pp 556-562.
Other characteristics, aspects, aims and advantages of the invention will become even clearer from reading the description which follows as well as the various specific examples, which are intended as an illustration and in no way as being limiting.
Agonist ligands which are specific for receptors of the RAR-xcex3 type, and which may be mentioned, are 6-3-(1-adamantyl)-4-hydroxyphenyl)-2-naphthanoic acid, (E)-4-(1-hydroxy-1-(5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2naphthyl)-2-propenyl)benzoic acid, 4-[(E)-2-(3-(1-adamantyl)-4-hydroxyphenyl)-1-propenyl]benzoic acid, 5xe2x80x2,5xe2x80x2,8xe2x80x2,8xe2x80x2-tetramethyl-5xe2x80x2,6xe2x80x2,7xe2x80x2,8xe2x80x2-tetrahydro-[2,2xe2x80x2]binaphthalenyl-6-carboxylic acid, 2-(5,5,8,8-tetramethyl-5,6,7,8-tetrahydro-naphthalen-2-yl)-benzo[b]thiophene-6-carboxylic acid, 4-(5,5,8,8-tetramethyl-5,6,7,8-tetrahydro-naphtho[2,3-b]thiophen-2-yl)benzoic acid, 6-(5,5,8,8-tetramethyl-5,6,7,8-tetrahydro-naphthalene-2-carbonyl)naphthalene-2-carboxylic acid, 3,7-dimethyl-7-(1,2,3,4-tetrahydro-1,4a,9b-trimethyl-1,4-methano-dibenzofuran-8-yl)-2,4,6-heptatrienoic acid, 6-(1,2,3,4-tetrahydro-1,4a,9b-trimethyl-1,4-methano-dibenzofuran-8-yl)-naphthalene-2-carboxylic acid, 6-[hydroxyimino-(5,5,8,8-tetramethyl-5,6,7,8-tetrahydro-naphthalen-2-yl)-methyl]naphthalene-2-carboxylic acid, 4-[(6-hydroxy-7-(1-adamantyl)-2-naphthyl]benzoic acid, 5-(5,5,8,8-tetramethyl-5,6,7,8-tetrahydro-anthracen-2-yl)-thiophene-2-carboxylic acid, (xe2x88x92)-6-[hydroxy-(5,5,8,8-tetramethyl-5,6,7,8-tetrahydro-naphthalen-2-yl)-methyl]-naphthalene-2-carboxylic acid, 4-[(2-oxo-2-(5,5,8,8-tetramethyl-5,6,7,8-tetrahydro-naphthalen-2-yl)-ethoxy]-benzoic acid, 4-[2-oxo-2-(5,5,8,8-tetramethyl-5,6,7,8-tetrahydro-naphthalen-2-yl)-acetylamino]-benzoic acid, 4-[2-fluoro-2-(5,5,8,8-tetramethyl-5,6,7,8-tetrahydro-naphthalen-2-yl)-acetylamino]-benzoic acid, 6-[3-(1-adamantyl-4-(2-hydroxypropyl)phenyl]-2-naphthoic acid, 6-[3-(1-adamantyl-4-(2,3-di-hydroxypropyl)phenyl]-2-naphthoic acid, 4-[3-hydroxy-(5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2-naphthyl)-1-propynyl]-benzoic acid, 4-[3-oxo-3-(5,5,8,8-tetramethyl-5,6,7,8-tetrahydro-naphthalen-2-yl)-prop-1-ynyl]benzoic acid, 4-[(3-(1-methylcyclohexyl)-4-hydroxyphenyl)ethenyl]-benzoic acid, 4-[(E)2-(3-(1-adamantyl)-4-hydroxyphenyl)-ethenyl]-benzoic acid, 4-[3-(1-adamantyl)-4-hydroxyphenylethynyl)-benzoic acid, 5-[3-(1-adamantyl)-4-hydroxyphenylethynyl]-2-thiophenecarboxylic acid, 5-[3-(1-adamantyl)-4-methoxyphenylethynyl]-2-thiophene-carboxylic acid, 4-[2-(3-tert-butyl-4-methoxyphenyl)-propenyl]benzoic acid, 4-{2-[4-methoxy-3-(1-methyl-cyclohexyl)phenyl]-propenyl}-benzoic acid, 6-[3-(1-adamantyl)-4-(3-methoxy-2-hydroxypropyl)-phenyl]-2-naphthoic acid, 2-hydroxy-4-[3-hydroxy-3-(5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2-naphthyl)-1-propynyl]-benzoic acid, 6-(5,5,8,8-tetramethyl-5,6,7,8-tetrahydro-naphthalen-2-yloxy)-naphthalene-2-carboxylic acid, 6-(5,5,8,8-tetramethyl-5,6,7,8-tetrahydro-naphthalen-2-ylsulphanyl)-naphthalene-2-carboxylic acid, 4-[2-propoxyimino-2-(5,5,8,8-tetramethyl-5,6,7,8-tetrahydro-naphthalen-2-yl)-acetylamino]benzoic acid, 6-(5,5,8,8-tetramethyl-5,6,7,8-tetrahydro-naphthalen-2-ylamino)naphthalene-2-carboxylic acid, 1-methyl-4-(5,5,8,8-tetramethyl-5,6,7,8-tetrahydroanthracen-2-yl)-1H-pyrrole-2-carboxylic acid, 2-methoxy-4-(5,5,8,8-tetramethyl-5,6,7,8-tetrahydro-anthracen-2-yl)-benzoic acid, 4-[2-nonyloxyimino-2-(5,5,8,8-tetramethyl-5,6,7,8-tetrahydro-naphthalen-2-yl)-acetylamino]-benzoic acid, (xe2x88x92)-2-hydroxy-4-[3-hydroxy-3-(5,5,8,8-tetramethyl-5,6,7,8-tetrahydro-naphthalen-2-yl)-prop-1-ynyl]-benzoic acid, (+)-2-hydroxy-4-[3-hydroxy-3-(5,5,8,8-tetramethyl-5,6,7,8-tetrahydro-naphthalen-2-yl)-prop-1-ynyl]-benzoic acid, 2-hydroxy-4-[3-hydroxy-3-(5,5,8,8-tetramethyl-5,6,7,8-tetrahydro-naphthalen-2-yl)-but-1-ynyl]-benzoic acid, 6-(3-bromo-5,5,8,8-tetramethyl-5,6,7,8-tetrahydro-naphthalen-2-yloxy)-naphthalene-2-carboxylic acid, 3-[(5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2-naphthyl)-2H-1-benzopyran]-7-carboxylic acid, 4-[3-(3,5-di-tert-butyl-4-hydroxy-phenyl)-prop-1-ynyl]-benzoic acid, 4-[3-(5,5,8,8-tetra-methyl-5,6,7,8-tetrahydro-naphthalen-2-yl)-prop-1-ynyl]-benzoic acid, 4-[3-(5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2-naphthyl)-1-propynyl]-salicylic acid, 4-[{3-(1-adamantyl)-4-(2-hydroxyethyl)phenyl}ethynyl]-benzoic acid and 4-[{3-(1-adamantyl)-4-(3-hydroxy-propyl)phenyl}ethynyl]-benzoic acid.
Preference is given, in the present invention, to using agonist ligands which are specific for receptors of the RAR-xcex3 type which exhibit a ratio R which is greater than or equal to 50. As such, preference is given to using 6-3-(1-adamantyl)-4-hydroxyphenyl)-2-naphthanoic acid, 6-(5,5,8,8-tetra-methyl-5,6,7,8-tetrahydro-naphthalene-2-carbonyl)-naphthalene-2-carboxylic acid, 6-(1,2,3,4-tetrahydro-1,4a,9b-trimethyl-1,4-methano-dibenzofuran-8-yl)-naphthalene-2-carboxylic acid, 6-[hydroxyimino-(5,5,8,8-tetramethyl-5,6,7,8-tetrahydro-naphthalen-2-yl)-methyl]-naphthalene-2-carboxylic acid, 5-(5,5,8,8-tetramethyl-5,6,7,8-tetrahydro-anthracen-2-yl)-thiophene-2-carboxylic acid, (xe2x88x92)-6-[hydroxy-(5,5,8,8-tetramethyl-5,6,7,8-tetrahydro-naphthalen-2-yl)-methyl]-naphthalene-2-carboxylic acid, 6-[3-(1-adamantyl-4-(2-hydroxypropyl)phenyl]-2-naphthoic acid, 6-[3-(1-adamantyl-4-(2,3-di-hydroxypropyl)phenyl]-2-naphthoic acid, 4-[3-(1-adamantyl)-4-hydroxyphenylethynyl]-benzoic acid, 5-[3-(1-adamantyl)-4-hydroxyphenylethynyl]-2-thiophenecarboxylic acid, 5-[3-(1-adamantyl)-4-methoxyphenylethynyl]-2-thiophenecarboxylic acid, 6-[3-(1-adamantyl)-4-(3-methoxy-2-hydroxypropyl)-phenyl]-2-naphthoic acid, 1-methyl-4-(5,5,8,8-tetra-methyl-5,6,7,8-tetrahydro-anthracen-2-yl)-1H-pyrrole-2-carboxylic acid, (xe2x88x92)-2-hydroxy-4-[3-hydroxy-3-(5,5,8,8-tetramethyl-5,6,7,8-tetrahydro-naphthalen-2-yl)-prop-1-ynyl]-benzoic acid and 2-hydroxy-4-[3-hydroxy-3-(5,5,8,8-tetramethyl-5,6,7,8-tetrahydro-naphthalen-2-yl)-but-1-ynyl)-benzoic acid.
6-3-(1-Adamantyl)-4-hydroxyphenyl)-2-naphthanoic acid is particularly preferred.
Thus, it will be possible to use the pharmaceutical composition comprising the agonist ligand which is specific for receptors of the RAR-xcex3 type when it is necessary to increase the rate of apoptosis. Naturally, this effect will only be achieved in cell populations in which apoptosis can be induced by activating receptors of the RAR-xcex3 type and therefore, in particular, in which receptors of the RAR-xcex3 type are present, as is the case, more specifically, in cells derived from the thymus.
It may prove to be necessary to increase the rate of apoptosis in two cases in the main. The first case relates to diseases or disorders which are linked to an inadequate rate of apoptosis. The second case relates to treatments which are required during a transplantation in order to decrease the effects tending to reject the transplanted organ. Thus, it is possible to consider increasing immunotolerance to the transplanted organ by decreasing the immune response of the T cells by means of inducing their rate of apoptosis.
Diseases or disorders which are linked to an inadequate rate of apoptosis, and which may more specifically be mentioned, are disorders which are due to precancerous conditions or cancers which can be the consequence of a proliferation of certain cell populations, autoimmune diseases, allergies or inflammatory reactions in which the number of cells causing damage is observed to be too high, or else in certain viral infections in which proteins of the virus have an antiapoptotic effect. Thus, in the case of autoimmune diseases, more specific mention may be made of insulin-dependent diabetes, active chronic hepatitis, rheumatoid arthritis, pemphigus, multiple sclerosis, myasthenia, systemic lupus erythematosus, Crohn""s disease and psoriasis. Actinic keratosis may be mentioned with regard to precancerous conditions. In the case of cancer, more specific mention may be made of lymphomas, carcinomas, such as cancer in the ENT sphere, and hormone-dependent tumours, such as ovarian cancers. Of the abovementioned viral infections, those which may in particular be cited are herpesviruses, adenoviruses and variola viruses (poxviruses). Allergies or inflammatory reactions which may be mentioned are contact eczema, atopic eczema, asthma and urticarias.
The composition according to the invention can be administered by the enteral, parenteral, topical or ocular route. Preference is given to packaging the pharmaceutical composition in a form which is suitable for administration by the systemic route (for injection or perfusion).
When administered by the enteral route, the composition, more specifically the pharmaceutical composition, can be in the form of tablets, hard gelatin capsules, coated tablets, syrups, suspensions, solutions, powders, granules, emulsions, microspheres or nanospheres, or lipid or polymeric vesicles which permit a controlled release. When administered by the parenteral route, the composition may be in the form of solutions or suspensions for perfusion or injection.
The agonist ligands which are specific for receptors of the RAR-xcex3 type and which are used in accordance with the invention are generally administered in a daily dose of from 0.01 mg/kg to 100 mg/kg of bodyweight, with the dose being given in from 1 to 3 administrations.
When administered by the topical route, the pharmaceutical or cosmetic composition according to the invention is more specifically intended for treating the skin and the mucous membranes and can be in the form of ointments, creams, milks, pomades, powders, imbibed buffers, solutions, gels, sprays, lotions or suspensions. It may also be in the form of microspheres or nanospheres, or lipid or polymeric vesicles, or of polymeric patches and hydrogels, which permit a controlled release. This composition, which is administered by the topical route, can be present either in anhydrous form or in aqueous form.
When administered by the ocular route, the composition is chiefly in the form of eye drops.
The agonist ligands which are specific for receptors of the RAR-xcex3 type are used by the topical or ocular route at a concentration which is generally between 0.001% and 10% by weight, preferably between 0.1 and 1% by weight, based on the total weight of the composition.
The present invention finally relates to a process for preventing and/or combating photoinduced or chronological ageing of the skin, characterized in that a cosmetic composition which induces apoptosis such as previously described, that is to say which comprises at least one agonist ligand which is specific for receptors of the RAR-xcex3 type in a cosmetically acceptable medium, is applied to the skin.
Naturally, the compositions as previously described may additionally comprise inert or even pharmacodynamically active additives or combinations of these additives, in particular: wetting agents; depigmenting agents such as hydroquinone, azelaic acid, caffeic acid or kojic acid; emollients; moisturizing agents such as glycerol, PEG 400, thiamorpholinone and its derivatives, or urea; antiseborrhoeic agents or anti-acne agents, such as S-carboxymethylcysteine, S-benzyl-cysteamine, and their salts or derivatives, or benzoyl peroxide; antifungal agents such as ketoconazole or the polymethylene-4,5-iso-thioazolidonin-3-ones; antibacterial agents, carotenoids and, in particular, xcex2-carotene; antipsoriatic agents such as anthralin and its derivatives; and, finally, eicosa-5,8,11,14-tetraynoic and eicosa-5,8,11-trynoic acids, and their esters and amides.
These compositions may also comprise taste-improving agents, preservatives such as esters of parahydroxybenzoic acid, stabilizers, moisture-regulating agents, pH-regulating agents, agents for modifying the osmotic pressure, emulsifying agents, UV-A and UV-B filters, antioxidants, such as xcex1-tocopherol, butylhydroxyanisole or butylhydroxytoluene.
Naturally, the skilled person will ensure that the possible compound(s) to be added to these compositions is/are selected such that the advantageous properties which are intrinsically attached to the present invention are not altered, or are not substantially altered, by the addition which is envisaged.